fix for wxComboBox flicker on create (patch 598891)

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@16685 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/msw/combobox.cpp

@@ -304,6 +304,11 @@ bool wxComboBox::Create(wxWindow *parent, wxWindowID id,
                         const wxValidator& validator,
                         const wxString& name)
 {
+    // pretend that wxComboBox is hidden while it is positioned and resized and
+    // show it only right before leaving this method because otherwise there is
+    // some noticeable flicker while the control rearranges itself
+    m_isShown = FALSE;
+
     // first create wxWin object
     if ( !CreateControl(parent, id, pos, size, style, validator, name) )
         return FALSE;
@@ -360,6 +365,9 @@ bool wxComboBox::Create(wxWindow *parent, wxWindowID id,
                                       );
     }
 
+    // and finally, show the control
+    Show(TRUE);
+
     return TRUE;
 }